So where to get php maven and the libraries? We recommend to receive it via maven itself. See the installation details.
However you may browse it manually: http://nexus.php-maven.org/index.html#view-repositories;release-repo1.php-maven.org.
Another way is to visit: the nexus. This is our repository server that not only contains PHP-Maven but ten thousands of well known projects and php libraries. All of them downloadable or usable by your PHP-Maven project.